Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
MMWR Morb Mortal Wkly Rep ; 69(28): 918-922, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32678072

RESUMO

To limit introduction of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), the United States restricted travel from China on February 2, 2020, and from Europe on March 13. To determine whether local transmission of SARS-CoV-2 could be detected, the New York City (NYC) Department of Health and Mental Hygiene (DOHMH) conducted deidentified sentinel surveillance at six NYC hospital emergency departments (EDs) during March 1-20. On March 8, while testing availability for SARS-CoV-2 was still limited, DOHMH announced sustained community transmission of SARS-CoV-2 (1). At this time, twenty-six NYC residents had confirmed COVID-19, and ED visits for influenza-like illness* increased, despite decreased influenza virus circulation.† The following week, on March 15, when only seven of the 56 (13%) patients with known exposure histories had exposure outside of NYC, the level of community SARS-CoV-2 transmission status was elevated from sustained community transmission to widespread community transmission (2). Through sentinel surveillance during March 1-20, DOHMH collected 544 specimens from patients with influenza-like symptoms (ILS)§ who had negative test results for influenza and, in some instances, other respiratory pathogens.¶ All 544 specimens were tested for SARS-CoV-2 at CDC; 36 (6.6%) tested positive. Using genetic sequencing, CDC determined that the sequences of most SARS-CoV-2-positive specimens resembled those circulating in Europe, suggesting probable introductions of SARS-CoV-2 from Europe, from other U.S. locations, and local introductions from within New York. These findings demonstrate that partnering with health care facilities and developing the systems needed for rapid implementation of sentinel surveillance, coupled with capacity for genetic sequencing before an outbreak, can help inform timely containment and mitigation strategies.


Assuntos
Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/virologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Vigilância de Evento Sentinela , Adolescente , Adulto , Idoso , COVID-19 , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções por Coronavirus/epidemiologia , Serviço Hospitalar de Emergência , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , SARS-CoV-2 , Análise de Sequência , Doença Relacionada a Viagens , Adulto Jovem
2.
Pediatr Dev Pathol ; 22(5): 431-439, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30922166

RESUMO

INTRODUCTION: In pregnancy, the presence of preeclampsia (PEC), systemic lupus erythematosus (SLE), and/or antiphospholipid antibody syndrome (APLS) is characterized by poor obstetric outcomes, with potential adverse effects for both mother and fetus. Although the histopathologic changes observed in these entities have been well established, the pathogenic mediators associated with tissue injury are poorly understood. METHODS: Forty placentas were evaluated, including 10 patients with preeclampsia, 9 with SLE, 11 with APLS, and 10 disease-free controls. Each case was subjected to a panel of immunohistochemical markers including C3b, C4d, Annexin A5, and C5b-9. Staining was graded on intensity and distribution. RESULTS: C4d staining was distinctly different among disease groups and controls. Moreover, 6/10 PEC cases, 3/9 SLE cases, and 4/11 APLS cases showed at least focal staining for C4d. All controls were negative. Annexin A5 (AnxA5) staining showed intrinsic variability in all disease groups, while 10/10 controls showed diffuse, strong staining (2+ or 3+). C3b staining was heterogeneous among groups. DISCUSSION: Previously, antiphospholipid antibody (aPLA)-associated pregnancy complications have been thought to be a consequence of a unique aPLA-mediated pathogenic mechanism. However, the immunohistochemical similarity (increased complement and decreased AnxA5 staining) observed in placentas from patients with APLS, PEC, and SLE suggests that aPLA-associated pregnancy complications may reflect a more general autoimmune mechanism.


Assuntos
Síndrome Antifosfolipídica , Lúpus Eritematoso Sistêmico , Placenta/patologia , Pré-Eclâmpsia , Complicações na Gravidez/imunologia , Anexina A5/análise , Anexina A5/biossíntese , Complemento C3b/análise , Complemento C3b/biossíntese , Complemento C4b/análise , Complemento C4b/biossíntese , Complexo de Ataque à Membrana do Sistema Complemento/análise , Complexo de Ataque à Membrana do Sistema Complemento/biossíntese , Feminino , Humanos , Imuno-Histoquímica , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/biossíntese , Gravidez , Estudos Retrospectivos
3.
Histochem Cell Biol ; 150(5): 529-543, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30121745

RESUMO

The antiphospholipid syndrome (APS) is an autoimmune thrombophilic disorder that was described as a diagnostic entity over 30 years ago. And yet the pathogenic mechanisms that are responsible for its clinical manifestations remain to be definitively established. The syndrome is defined by (1) the concurrence of vascular thrombosis and/or pregnancy complications together with (2) positivity for immunoassays and coagulation tests that were derived from clinical observations of two anomalous laboratory test results-specifically, false positivity for syphilis infection in uninfected individuals and the finding of inhibitors of blood coagulation in patients who lacked any bleeding tendencies. Over the years, these were standardized into immunoassays and coagulation assays for APS. Here, we describe how prior knowledge of the immunologic and coagulation aspects of the disorder led to research involving a range of imaging modalities including light microscopy, immunohistochemistry, confocal scanning laser microscopy, transmission and scanning electron microscopy, and atomic force microscopy. In turn, the results from those studies led to a "reimagining" of APS that has advanced the understanding of pathogenic mechanisms of the disorder and has led to the development of novel mechanistically based diagnostics along with potential new treatment approaches that target disease mechanisms.


Assuntos
Síndrome Antifosfolipídica/diagnóstico , Síndrome Antifosfolipídica/patologia , Imunoensaio , Microscopia , Síndrome Antifosfolipídica/terapia , Humanos , Imagem Molecular
4.
Rheumatology (Oxford) ; 57(1): 120-124, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29045759

RESUMO

Objectives: HCQ has been described as having a beneficial effect in patients with APS but its mechanism of action is unclear. We hypothesized that HCQ may have effects on subnormal angiogenesis, inflammation and haemostatic biomarkers seen in APS. The aim of our study was to assess laboratory markers [annexin A5 (AnxA5) anticoagulant activity, tissue factor (TF) levels, thromboelastography (TEG), CRP, Bb, C3a and VEGF] in HCQ-naïve patients with aPL at baseline and after commencing HCQ. Methods: Twenty-two patients with aPL [20 female, 2 male, median age 55 (range 18-70) years] had blood taken pre- and 3 months after starting HCQ 200 mg daily. Results: Soluble TF levels were significantly reduced comparing baseline and 3 months after HCQ commencement [401.8 (152.8) vs 300.9 (108) pg/ml (P = 0.010)]. No significant changes were found in the following [reported as pre- and post-HCQ commencement, mean (s.d.)]: AnxA5 anticoagulant ratio [187.1 (29.5) vs 193 (31) (P = 0.157)], anti-domain1 ß2 glycoprotein1 IgG activity [1.8 (2) vs 1.2 (1.4) µg/ml (P = 0.105)], complement C3a-des-Arg [147.8 (84.5) vs 154.4 (88.1) ng/ml (P = 0.905)], complement Bb [1.3 (0.7) vs 1.1 (0.7) µg/ml (P = 0.422)], VEGF [68.8 (40) vs 59.4 (19.6) pg/ml (P = 0.454)] and CRP [7 (3.5) vs 7 (3.9) µg/ml (P = 0.917)]. TEG results including TEG reaction time, achievement of clot firmness, TEG maximum amplitude and TEG percentage lysis 30 and 60 min after maximum amplitude showed no significant difference. Conclusion: HCQ significantly reduced soluble TF levels in patients with aPL. No significant change was observed in AnxA5 activity, anti-domain 1 IgG activity, TEG, CRP, complement Bb and C3a-des-Arg, and VEGF. Further studies of a larger patient cohort are needed.


Assuntos
Síndrome Antifosfolipídica/tratamento farmacológico , Antirreumáticos/uso terapêutico , Hidroxicloroquina/uso terapêutico , Adolescente , Adulto , Idoso , Anexina A5/metabolismo , Anticorpos Antinucleares/imunologia , Anticorpos Antifosfolipídeos/imunologia , Síndrome Antifosfolipídica/imunologia , Síndrome Antifosfolipídica/metabolismo , Proteína C-Reativa/metabolismo , Complemento C3a/imunologia , Proteínas do Sistema Complemento/imunologia , Hemostasia , Humanos , Imunoglobulina G/imunologia , Pessoa de Meia-Idade , Neovascularização Fisiológica , Estudos Prospectivos , Tromboelastografia , Tromboplastina/metabolismo , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto Jovem , beta 2-Glicoproteína I/imunologia
5.
BMC Med ; 15(1): 54, 2017 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-28279213

RESUMO

BACKGROUND: Patients with the lupus anticoagulant (LA) are at an increased risk of thrombotic events, which in turn increase the risk of death. Understanding the determinants of thrombotic risk in patients with LA may pave the way towards targeted thromboprophylaxis. In the Vienna Lupus Anticoagulant and Thrombosis Study (LATS), we systematically evaluate risk factors for thrombotic events in patients with LA. METHODS: We followed 150 patients (mean age: 41.3 years, female gender: n = 122 (81.3%), history of thrombosis or pregnancy complications: n = 111 (74.0%)), who tested repeatedly positive for LA until development of thrombosis, death, or censoring. The primary endpoint was a composite of arterial or venous thrombotic events (TEs). RESULTS: During a median follow-up of 9.5 years (range: 12 days-13.6 years) and 1076 person-years, 32 TEs occurred (arterial: n = 16, venous: n = 16; cumulative 10-year TE incidence: 24.3%). A prolonged lupus-sensitive activated partial thromboplastin time (aPTT-LA) (adjusted subdistribution hazard ratio (SHR) = 2.31, 95% CI: 1.07--5.02), diabetes (adjusted SHR = 4.39, 95% CI: 1.42-13.57), and active smoking (adjusted SHR = 2.31, 95% CI: 1.14-5.02) emerged as independent risk factors of both arterial and venous thrombotic risk. A risk model that includes a prolonged lupus-sensitive aPTT, smoking, and diabetes enabled stratification of LA patients into subgroups with a low, intermediate, and high risk of thrombosis (5-year TE risk of 9.7% (n = 77), 30.9% (n = 51), and 56.8% (n = 22). CONCLUSIONS: Long-term thrombotic risk in patients with LA is clustered within subjects harboring typical cardiovascular risk factors in addition to a prolonged lupus-sensitive aPTT, whereas patients with none of these risk factors represent a large subgroup with a low risk of thrombosis.


Assuntos
Inibidor de Coagulação do Lúpus/efeitos adversos , Trombose/epidemiologia , Trombose/etiologia , Adulto , Doenças Cardiovasculares/complicações , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
6.
Circulation ; 131(2): 182-9, 2015 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-25301832

RESUMO

BACKGROUND: There are few data on the relationship of antiphospholipid antibodies (aPLs) to pathologically proven brain infarcts. We tested the hypothesis that aPLs are associated with a higher odds of brain infarcts among older, community-dwelling individuals who came to autopsy. METHODS AND RESULTS: Specimens and clinical and pathological data were derived from 607 deceased subjects (mean age at death, 89 years; 66% women) who were participating in 1 of 2 cohort studies of aging (Rush Memory and Aging Project and Religious Orders Study) and had agreed to brain autopsy. Brain infarcts were identified on gross and microscopic examinations, and severity of cerebral vessel disease (atherosclerosis, arteriolosclerosis) was graded. Four clinically used aPLs were measured longitudinally: 3 in serum (anticardiolipin antibodies, ß2-glycoprotein I, and anti-phosphatidyl-serine) and 1 in plasma (lupus anticoagulant). A quarter of subjects (142 of 607, 23%) had at least 1 aPL present at baseline (median time interval from baseline to death, 4.6 years), and three quarters of these subjects had persistently positive measures over time. In a logistic regression analysis, baseline aPL positivity did not increase the odds of brain infarcts (odds ratio=1.08; 95% confidence interval, 0.74-1.58; P=0.19) or of gross or microscopic infarcts separately. Findings were essentially unchanged when considering number of baseline aPLs, aPLs proximate to death, and persistence of aPLs. Associations did not differ among subjects with increased severity of vessel disease. CONCLUSION: Overall, we did not find evidence that aPLs increase the odds of pathological brain infarcts in older people.


Assuntos
Anticorpos Antifosfolipídeos/sangue , Infarto Encefálico/imunologia , Idoso , Idoso de 80 Anos ou mais , Autoantígenos/imunologia , Autopsia , Encéfalo/patologia , Infarto Encefálico/patologia , Artérias Cerebrais/patologia , Estudos de Coortes , Comorbidade , Feminino , Humanos , Arteriosclerose Intracraniana/epidemiologia , Inibidor de Coagulação do Lúpus/sangue , Masculino , Fosfatidilserinas/imunologia , Estudos Prospectivos , Método Simples-Cego , beta 2-Glicoproteína I/imunologia
7.
Transfus Apher Sci ; 55(1): 114-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27156966

RESUMO

OBJECTIVES: Factor V (FV) plays an important role in coagulation. As no purified concentrate is available to restore critical FV levels, the main blood product used to replace FV is plasma. The aim of the present in vitro study was to compare the efficacy of the different available plasma products on the reversal of moderate and severe FV deficiency as assessed by ROTEM® and FV levels. METHODS: Five different plasma products (6 batches of each) were compared to determine their effectiveness in replacing FV in plasma moderately or severely deficient in FV. Effectiveness was measured using the ROTEM® EXTEM clotting time (CT) and a factor V assay. RESULTS: FFP, plasma frozen within 24 hours (FP24), Octaplas (solvent/detergent treated pooled plasma), as well as Octaplas and FP24 thawed and stored for 5 days (Octaplas TP and TP), were all used for in vitro replacement of FV. TP was significantly less effective at reversing a prolonged EXTEM CT and FV levels in FV deficient plasma than other tested products. There were no significant differences in EXTEM CT between Octaplas and Octaplas TP, while factor V activity was significantly lower in the Octaplas TP. There was no significant difference between Octaplas and FFP for EXTEM CT or FV activity. CONCLUSIONS: Octaplas and Octaplas TP appear to have an equivalent ability to improve the EXTEM CT and could be considered as a treatment alternative to FFP in patients with FV deficiency.


Assuntos
Preservação de Sangue , Detergentes/química , Deficiência do Fator V/sangue , Fator V/metabolismo , Plasma/metabolismo , Fator V/química , Feminino , Humanos , Masculino , Plasma/química
8.
Am J Pathol ; 184(12): 3359-75, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25451155

RESUMO

Progression to an angiogenic state is a critical event in tumor development, yet few patient characteristics have been identified that can be mechanistically linked to this transition. Antiphospholipid autoantibodies (aPLs) are prevalent in many human cancers and can elicit proangiogenic expression in several cell types, but their role in tumor biology is unknown. Herein, we observed that the elevation of circulating aPLs among breast cancer patients is specifically associated with invasive-stage tumors. By using multiple in vivo models of breast cancer, we demonstrated that aPL-positive IgG from patients with autoimmune disease rapidly accelerates tumor angiogenesis and consequent tumor progression, particularly in slow-growing avascular tumors. The action of aPLs was local to the tumor site and elicited leukocytic infiltration and tumor invasion. Tumor cells treated with aPL-positive IgG expressed multiple proangiogenic genes, including vascular endothelial growth factor, tissue factor (TF), and colony-stimulating factor 1. Knockdown and neutralization studies demonstrated that the effects of aPLs on tumor angiogenesis and growth were dependent on tumor cell-derived TF. Tumor-derived TF was essential for the development of pericyte coverage of tumor microvessels and aPL-induced tumor cell expression of chemokine ligand 2, a mediator of pericyte recruitment. These findings identify antiphospholipid autoantibodies as a potential patient-specific host factor promoting the transition of indolent tumors to an angiogenic malignant state through a TF-mediated pathogenic mechanism.


Assuntos
Anticorpos Antifosfolipídeos/química , Neoplasias/metabolismo , Neovascularização Patológica , Tromboplastina/metabolismo , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Progressão da Doença , Endotoxinas/química , Feminino , Regulação da Expressão Gênica , Humanos , Imunoglobulina G/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Microscopia de Fluorescência , Transplante de Neoplasias
10.
J Cell Physiol ; 228(10): 1949-55, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23526453

RESUMO

The atomic force microscope (AFM), invented in 1986, and a member of the scanning probe family of microscopes, offers the unprecedented ability to image biological samples unfixed and in a hydrated environment at high resolution. This opens the possibility to investigate biological mechanisms temporally in a heretofore unattainable resolution. We have used AFM to investigate: (1) fundamental issues in cell biology (secretion) and, (2) the pathological basis of a human thrombotic disease, the antiphospholipid syndrome (APS). These studies have incorporated the imaging of live cells at nanometer resolution, leading to discovery of the "porosome," the universal secretory portal in cells, and a molecular understanding of membrane fusion from imaging the interaction and assembly of proteins between opposing lipid membranes. Similarly, the development of an in vitro simulacrum for investigating the molecular interactions between proteins and lipids has helped define an etiological explanation for APS. The prime importance of AFM in the success of these investigations will be presented in this manuscript, as well as a discussion of the limitations of this technique for the study of biomedical samples.


Assuntos
Técnicas Citológicas/métodos , Microscopia de Força Atômica/métodos , Síndrome Antifosfolipídica/patologia , Humanos , Trombose/patologia
11.
Semin Thromb Hemost ; 39(2): 191-201, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23397553

RESUMO

Acquired von Willebrand syndrome (AVWS) is an acquired bleeding disorder, first reported in 1968, with clinical and laboratory features similar to inherited von Willebrand disease. This rare bleeding disorder occurs mainly in patients with underlying lymphoproliferative, cardiovascular, myeloproliferative, and immunologic disorders. In contrast to acquired hemophilia A, AVWS is rarely associated with measurable anti-von Willebrand factor inhibitors. In most instances, AVWS is identified because of bleeding complications: in fact, more than 80% of the patients with this syndrome are active bleeders. Recurrent bleeding episodes occur in approximately 20 to 33% of patients with AVWS, especially following major trauma and surgery. Because of the heterogeneous mechanisms of AVWS, more than one therapeutic approach is often required to prevent or treat acute bleedings. Remission from some forms of AVWS can be obtained when the underlying disorders are treated.


Assuntos
Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/terapia , Humanos , Doenças de von Willebrand/sangue , Fator de von Willebrand/metabolismo
12.
Blood ; 117(25): 6777-85, 2011 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-21540459

RESUMO

The acquired von Willebrand syndrome (AVWS) is a bleeding disorder that is frequently unrecognized or is misdiagnosed as von Willebrand disease. AVWS is characterized by structural or functional defects of von Willebrand factor (VWF) that are secondary to autoimmune, lymphoproliferative or myeloproliferative, malignant, cardiovascular, or other disorders. VWF abnormalities in these disorders can result from (1) antibody-mediated clearance or functional interference, (2) adsorption to surfaces of transformed cells or platelets, or (3) increased shear stress and subsequent proteolysis. Diagnosis can be challenging as no single test is usually sufficient to prove or exclude AVWS. Furthermore, there are no evidence-based guidelines for management. Treatments of the underlying medical condition, including chemo/radiotherapy, surgery, or immunosuppressants can result in remission of AVWS, but is not always feasible and successful. Because of the heterogeneous mechanisms of AVWS, more than one therapeutic approach is often required to treat acute bleeds and for prophylaxis during invasive procedures; the treatment options include, but are not limited to, desmopressin, VWF-containing concentrates, intravenous immunoglobulin, plasmapheresis or recombinant factor VIIa. Here, we review the management of AVWS with an overview on the currently available evidence and additional considerations for typical treatment situations.


Assuntos
Doenças Hematológicas/diagnóstico , Doenças Hematológicas/terapia , Hemostáticos/uso terapêutico , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/terapia , Animais , Desamino Arginina Vasopressina/uso terapêutico , Fator VIIa/uso terapêutico , Doenças Hematológicas/epidemiologia , Doenças Hematológicas/patologia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Plasmaferese , Proteínas Recombinantes/uso terapêutico , Síndrome , Doenças de von Willebrand/epidemiologia , Doenças de von Willebrand/patologia , Fator de von Willebrand/uso terapêutico
13.
Neuroepidemiology ; 40(2): 73-84, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23095514

RESUMO

The overall goal of the Antiphospholipid Antibodies, Brain Infarcts, and Cognitive and Motor Decline in Aging study is to test the hypothesis that antiphospholipid antibodies (aPL) are associated with an increased risk of pathologically proven brain infarcts and are related to cognitive and motor decline in aging. Putative biologic mechanisms underlying the association of aPL with infarcts and the relation of aPL with clinical outcomes of cognitive and motor impairment, including vascular and other processes, will be examined. The design of this longitudinal, clinical-pathologic study involves quantifying four aPL assays, and relating these to brain infarcts, and to cognitive and motor decline. Vascular mechanisms assessed using antemortem magnetic resonance neuroimaging and postmortem neuropathology, as well as nonvascular mechanisms of inflammation and blood-brain barrier permeability alterations will be examined as plausible mediators of the relation of aPL to cognitive and motor impairment. We will take advantage of antemortem biological specimens (longitudinally collected sera and plasma from which aPL, annexins, C-reactive protein, and matrix metalloproteinases will be quantified), and clinical, neuroimaging, and postmortem neuropathologic data from about 800 elderly, community-dwelling women and men who have agreed to brain autopsy at the time of death, participating in one of two ongoing studies of aging: the Religious Orders Study and the Memory and Aging Project.


Assuntos
Envelhecimento/sangue , Envelhecimento/patologia , Anticorpos Antifosfolipídeos/sangue , Infarto Cerebral/sangue , Transtornos Cognitivos/sangue , Projetos de Pesquisa Epidemiológica , Transtornos dos Movimentos/patologia , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Encéfalo/patologia , Infarto Cerebral/patologia , Transtornos Cognitivos/patologia , Estudos de Coortes , Demência/sangue , Demência/patologia , Feminino , Humanos , Estudos Longitudinais/métodos , Imageamento por Ressonância Magnética , Masculino , Transtornos dos Movimentos/sangue
14.
Blood ; 115(11): 2292-9, 2010 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-19965621

RESUMO

Annexin A5 (AnxA5) is a potent anticoagulant protein that crystallizes over phospholipid bilayers (PLBs), blocking their availability for coagulation reactions. Antiphospholipid antibodies disrupt AnxA5 binding, thereby accelerating coagulation reactions. This disruption may contribute to thrombosis and miscarriages in the antiphospholipid syndrome (APS). We investigated whether the antimalarial drug, hydroxychloroquine (HCQ), might affect this prothrombotic mechanism. Binding of AnxA5 to PLBs was measured with labeled AnxA5 and also imaged with atomic force microscopy. Immunoglobulin G levels, AnxA5, and plasma coagulation times were measured on cultured human umbilical vein endothelial cells and a syncytialized trophoblast cell line. AnxA5 anticoagulant activities of APS patient plasmas were also determined. HCQ reversed the effect of antiphospholipid antibodies on AnxA5 and restored AnxA5 binding to PLBs, an effect corroborated by atomic force microscopy. Similar reversals of antiphospholipid-induced abnormalities were measured on the surfaces of human umbilical vein endothelial cells and syncytialized trophoblast cell lines, wherein HCQ reduced the binding of antiphospholipid antibodies, increased cell-surface AnxA5 concentrations, and prolonged plasma coagulation to control levels. In addition, HCQ increased the AnxA5 anticoagulant activities of APS patient plasmas. In conclusion, HCQ reversed antiphospholipid-mediated disruptions of AnxA5 on PLBs and cultured cells, and in APS patient plasmas. These results support the concept of novel therapeutic approaches that address specific APS disease mechanisms.


Assuntos
Anexina A5/metabolismo , Anticorpos Antifosfolipídeos/imunologia , Anticoagulantes/metabolismo , Antimaláricos/farmacologia , Hidroxicloroquina/farmacologia , Anexina A5/ultraestrutura , Antimaláricos/metabolismo , Síndrome Antifosfolipídica/sangue , Coagulação Sanguínea/efeitos dos fármacos , Células Cultivadas , Cristalização , Humanos , Hidroxicloroquina/metabolismo , Bicamadas Lipídicas/metabolismo , Microscopia de Força Atômica , Ligação Proteica/efeitos dos fármacos
15.
Am J Obstet Gynecol ; 205(6): 576.e7-14, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21871597

RESUMO

OBJECTIVE: Antibody-mediated disruption of the annexin A5 anticoagulant shield has been posited to be a thrombogenic mechanism in the antiphospholipid syndrome. We recently showed that the antimalarial drug, hydroxychloroquine, dissociates antiphospholipid immune complexes and restores annexin A5 binding to planar phospholipid bilayer. Using quantitative immunoassays, we demonstrated similar effects on BeWo trophoblasts. We therefore, investigated the effects of the drug on localization of annexin A5 in primary cultures of human placental syncytiotrophoblasts. STUDY DESIGN: Laser confocal microscopy with computer-based morphometric analysis was used to localize annexin A5 and antiphospholipid antibodies on syncytiotrophoblasts exposed to polyclonal and monoclonal antiphospholipid and control immunoglobulin-Gs. RESULTS: Hydroxychloroquine reversed the effects of the antiphospholipid antibodies on the syncytiotrophoblasts by markedly reducing immunoglobulin-G binding and restoring annexin A5 expression. CONCLUSION: These results provide the first morphologic evidence for this effect of hydroxychloroquine on human placental syncytiotrophoblasts and support the possibility of novel treatments that target antiphospholipid antibody binding.


Assuntos
Anexina A5/metabolismo , Anticorpos Antifosfolipídeos/metabolismo , Síndrome Antifosfolipídica/imunologia , Hidroxicloroquina/farmacologia , Trofoblastos/efeitos dos fármacos , Anticorpos Antifosfolipídeos/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Complexo Antígeno-Anticorpo/efeitos dos fármacos , Complexo Antígeno-Anticorpo/imunologia , Antimaláricos/farmacologia , Síndrome Antifosfolipídica/tratamento farmacológico , Células Cultivadas , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Microscopia Confocal , Gravidez , Trofoblastos/citologia , Trofoblastos/imunologia
16.
Am J Obstet Gynecol ; 205(5): 485.e17-23, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21784397

RESUMO

OBJECTIVE: The objective of the study was to investigate whether resistance to annexin A5 anticoagulant activity (AnxA5) occurs in women with histories for obstetric complications of antiphospholipid syndrome (Obs-APS) and whether this correlates with antibody recognition of domain 1 of ß2-glycoprotein. STUDY DESIGN: One hundred thirty-six women with antiphospholipid antibodies, including 70 with histories for Obs-APS and 30 controls, were investigated. RESULTS: Women with Obs-APS showed resistance to AnxA5 activity (median, 216%; range, 130-282% vs controls; median, 247%; range, 217-283%; P < .0001) and elevated levels of anti-domain I immunoglobulin (Ig) G (optical density: median, 0.056; range, 0.021-0.489 vs median, 0.042; range, 0.020-0.323; P = .002). Those in the lowest tertile of AnxA5 anticoagulant ratios had an odds ratio for Obs-APS of 58.0 (95% confidence interval, 3.3-1021.5). There was an inverse correlation between levels of annexin A5 anticoagulant activity and anti-domain I IgG. CONCLUSION: Resistance to AnxA5 anticoagulant activity is associated with antibody recognition of domain I of ß2-glycoprotein I and identifies a subset of women with histories for Obs-APS.


Assuntos
Anexina A5/metabolismo , Anticorpos Antifosfolipídeos/imunologia , Síndrome Antifosfolipídica/imunologia , Complicações na Gravidez/imunologia , Adulto , Idoso , Anticorpos Antifosfolipídeos/metabolismo , Síndrome Antifosfolipídica/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Complicações na Gravidez/metabolismo
17.
Blood ; 112(5): 1687-95, 2008 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-18577708

RESUMO

Treatment with the antimalarial drug hydroxychloroquine (HCQ) has been associated with reduced risk of thrombosis in the antiphospholipid (aPL) syndrome (APS) and, in an animal model of APS, with reduction of experimentally induced thrombosis. Recognition of beta2-glycoprotein I (beta2GPI) by aPL antibodies appears to play a major role in the disease process. We therefore used the techniques of ellipsometry and atomic force microscopy (AFM) to investigate whether HCQ directly affects the formation of aPL IgG-beta2GPI complexes on phospholipid bilayers. HCQ, at concentrations of 1 mug/mL and greater, significantly reduced the binding of aPL-beta2GPI complexes to phospholipid surfaces and THP-1 (human acute monocytic leukemia cell line) monocytes. The drug also reduced the binding of the individual proteins to bilayers. This HCQ-mediated reduction of binding was completely reversed when the HCQ-protein solutions were dialyzed against buffer. HCQ also caused modest, but statistically significant, reductions of clinical antiphospholipid assays. In conclusion, HCQ reduces the formation of aPL-beta2GPI complexes to phospholipid bilayers and cells. This effect appears to be due to reversible interactions between HCQ and the proteins and may contribute to the observed reduction of thrombosis in human and experimental APS. These results support the possibility that HCQ, or analogous molecules, may offer novel nonanticoagulant therapeutic strategies for treating APS.


Assuntos
Anticorpos Antifosfolipídeos/metabolismo , Hidroxicloroquina/farmacologia , Fosfolipídeos/metabolismo , beta 2-Glicoproteína I/metabolismo , Anticorpos Antifosfolipídeos/sangue , Anticorpos Antifosfolipídeos/química , Anticoagulantes/farmacologia , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/efeitos dos fármacos , Complexo Antígeno-Anticorpo/metabolismo , Antimaláricos/farmacologia , Síndrome Antifosfolipídica/sangue , Síndrome Antifosfolipídica/tratamento farmacológico , Linhagem Celular , Humanos , Técnicas In Vitro , Bicamadas Lipídicas/metabolismo , Microscopia de Força Atômica , Complexos Multiproteicos/química , Complexos Multiproteicos/efeitos dos fármacos , Complexos Multiproteicos/metabolismo , Ligação Proteica/efeitos dos fármacos , beta 2-Glicoproteína I/química
18.
J Thromb Haemost ; 18(11): 2828-2839, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33462974

RESUMO

This guidance focuses on methodological aspects of lupus anticoagulant (LA) testing, as well as interpretation of results for clinicians. The main changes in how to test for LA compared with the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee 2009 guidelines, in the preanalytical phase are more detailed recommendations on how to handle testing in anticoagulated patients, and the timing of testing. Also, routine coagulation tests are advised to obtain more information on the coagulation background of the patient, and when necessary, anti-Xa activity measurement for heparins or specific assays for direct oral anticoagulants should be performed. The three-step procedure with two test systems (diluted Russell's viper venom time and activated partial thromboplastin time [aPTT]) is essentially not changed. Silica remains the preferable activator in the aPTT assays, but ellagic acid is not excluded. We advise simultaneous performance of the mixing and confirmatory step, in each sample with a prolonged screening test. The confirmatory step can also be performed on a mixture of patient plasma and normal pooled plasma. Cutoff values should be established in-house on at least 120 normals, with transference of the manufacturer's cutoffs as an alternative. Reporting of results has not been changed, although more attention is focused on what clinicians should know. Patient selection for LA testing has been expanded.


Assuntos
Síndrome Antifosfolipídica , Trombose , Síndrome Antifosfolipídica/diagnóstico , Testes de Coagulação Sanguínea , Humanos , Inibidor de Coagulação do Lúpus , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Padrões de Referência , Trombose/diagnóstico
19.
Cancer Cell ; 38(5): 661-671.e2, 2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-32997958

RESUMO

Patients with cancer may be at increased risk of severe coronavirus disease 2019 (COVID-19), but the role of viral load on this risk is unknown. We measured SARS-CoV-2 viral load using cycle threshold (CT) values from reverse-transcription polymerase chain reaction assays applied to nasopharyngeal swab specimens in 100 patients with cancer and 2,914 without cancer who were admitted to three New York City hospitals. Overall, the in-hospital mortality rate was 38.8% among patients with a high viral load, 24.1% among patients with a medium viral load, and 15.3% among patients with a low viral load (p < 0.001). Similar findings were observed in patients with cancer (high, 45.2% mortality; medium, 28.0%; low, 12.1%; p = 0.008). Patients with hematologic malignancies had higher median viral loads (CT = 25.0) than patients without cancer (CT = 29.2; p = 0.0039). SARS-CoV-2 viral load results may offer vital prognostic information for patients with and without cancer who are hospitalized with COVID-19.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/complicações , Hospitalização/estatística & dados numéricos , Neoplasias/mortalidade , Pneumonia Viral/complicações , Carga Viral , Idoso , Idoso de 80 Anos ou mais , COVID-19 , Estudos de Casos e Controles , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Neoplasias/virologia , New York/epidemiologia , Pandemias , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Prognóstico , Estudos Retrospectivos , SARS-CoV-2 , Taxa de Sobrevida
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa